Marine Applications of Indian Satellite RISAT

by OldSailor on April 30, 2009

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India launched Radar Imaging Satellite RISAT-2 on April 20. Most of the media reported RISAT-2 as a spy satellite, because the satellite’s clear imagery can also be used for military applications.Shocked by sea based attacks at Mumbai on November 26, 2008 India has accelerated the launch of RISAT-2 before the launch of RISAT-1 which focuses on agricultural application.

India launched its first operational Indian Remote Sensing (IRS) Satellite, IRS-1A on March 17, 1988. IRS satellites were designed to provide data in the visible and near infrared region of Electro Magnetic spectrum. Electro-optic imaging sensors working in this spectrum, can only collect data during day time and can not penetrate through clouds and fog to collect data.

To ensure non stop collection of remote sensing data, RISAT-2 was launched. RISAT uses Synthetic Aperture Radar (SAR) working in microwave bands. The atmosphere is very transparent to microwaves irrespective of day,night,cloud and fog conditions.

Some interesting features of RISAT-2 are:

A new class of remote sensing satellite.

An eye in the sky, all time, all weather, see all, surveillance satellite.

Launched by Polar Satellite Launch Vehicle, PSLV – C 12.

Orbits at an altitude of 550 km with an inclination of 41 degree.

Weighs 300 kg.

Orbit period of 90 minutes.

The satellite has been built with the cooperation from Israel Aerospace Industries.

The satellite is reported to be a replica of Israeli TECSAR satellite launched by Indian Space Research Organization (ISRO) in January this year.

The satellite will enhance ISRO’s capability for earth observation, especially during floods, cyclones, landslides and in disaster management in a more effective way.

RISAT has many applications in the field of agriculture,oceanography,forestry,geology and hydrology.

Marine applications of RISAT:

Monitoring oil spills in the sea: Oil spill images can be viewed clearly and the source of the spill also can be found out.

Ships at sea can be detected and tracked.

Natural seepage from oil deposits can also be observed to assess suitable locations for offshore drilling.

Marine scientists can study wind,current,eddies and internal waves through the radar backscatter from the ocean surface.

In shallow waters, imagery can be used to study the sea bottom topography. Altimeters using SAR can also be used for ocean floor mapping.

From the imagery, ocean waves and their direction of displacement can be found out for wave forecasting and for marine climatology.

In Arctic and Antarctic area, ice formation including ice type and ice concentration can be assessed for navigation in ice-infested waters.